Abstract. We consider lattice spin systems with short range but random and unbounded
interactions.\newline
{\it Statics} : We give an elementary proof of uniqueness of Gibbs
measures at high temperature or strong magnetic fields, and of the
exponential decay of the corresponding quenched correlation functions.
The analysis is based on the study of disagreement percolation
(as initiated in van den Berg--Maes (1994)).\newline
{\it Dynamics} : We give criteria
for ergodicity of spin flip dynamics and estimate the
speed of convergence to the unique invariant measure. We find for
this convergence a stretched exponential in time
for a class of ``directed'' dynamics
(such as in the disordered Toom or
Stavskaya model). For the general case, we show
that the relaxation is faster than any power in time. No
assumptions of reversibility are made.\\
The methods are based on relating the problem to an oriented
percolation problem (contact process) and
(for the general case) using a slightly
modified version of the multiscale analysis of e.g. Klein (1993).